The method recently formed the plot for an episode of the BBC crime drama 'The Shadow Line'.

Mills, the boss of the 'Flowers Gang', was described as one of Britain's most wanted fugitives before he was arrested in Holland in March last year.

Between June 2006 and November 2007, Mills' syndicate moved 18 tons of cannabis through UK ports, making £22million in profits.

Mills also oversaw a massive money-laundering operation, setting up companies in international tax havens to hide the gang's profits.

But they made so much money they could they could not dispose of it quickly enough. When police raided safe houses they recovered wads of £20 notes literally rotting away.

Although he was photographed at 'board meetings' at the group's Surrey base, Mills spent most of his time in Holland liaising with his Dutch suppliers.

When police swooped on his co-conspirators, he was able to evade capture, but was finally arrested in Amsterdam last year.

Terrence Bowler, left, was last year jailed for 16 years for his role in the operation, while Mark Kinnimont was sentenced to 14 years

Mills' deputy Terrence Bowler was jailed for 16 years in March 2010, while two more gang 'directors', Peter Moran and Mark Kinnimont, each received 14-year sentences.

After he was convicted by the jury, Judge Gregory Stone, QC, told Mills: 'I think you are under no illusions about the position you are in.'

Mills replied: 'That's correct, Judge Stone.'

The skunk weed was grown in vast greenhouses hidden among legitimate crops.

The gang paid £2,200 per kg for the drug, before selling it on to regional wholesalers in the UK at £3,400 who traded it on the street for £5,760 per kg.

Regular shipments arrive at Harwich port in East Anglia, with shrink-wrapped packages of skunk hidden inside boxes of flowers.

The crates were delivered to a warehouse in Chatham, Kent, where the drugs were separated out and ferried on to secure lock-ups in Kingston, Worcester Park, Epsom and Ashtead in Surrey.

Dirty money: The gang had so much cash they were not able to dispose of it quickly enough, with some being left to rot

When a shipment of drugs was intercepted in July 2008, the gang simply switched their operation to a warehouse in Leeds, via the port of Hull.

Prosecutor Timothy Cray said: 'If the man pushing cannabis on the street, the small-time dealer, is equivalent to the market trader selling his fruit and veg outside London Bridge station, then this group were the big players, the Tesco.

'Anthony Mills was the director of this Tesco.'

The gang's 'board of directors' was under surveillance at Cafe Rouge in Esher, Surrey, on October 22, 2008, as Mills totted up the profits on a calculator.

Police also followed both Mills and Bowler to Geneva in Switzerland, where they were spotted having lunch with employees of a bank where some of the money was laundered.

Mills' gang's activities were echoed in an episode of she Shadow Line, which stars Chiwetel Ejiofor, left, Stephen Rea, centre, and Christopher Eccleston

Detectives are now liaising with colleagues in other countries to try to unravel the network of overseas assets built up by the gang, ahead of confiscation hearings.

The organisation's turnover in the period covered by the investigation is estimated at £61m, and its profit at £22m.

Mills, of no fixed address, was unanimously convicted of conspiracy to import cannabis and conspiracy to conceal the proceeds of drug supply.

He earlier admitted laundering money on behalf of others.

During the trial he tried to claim that he had only helped the gang to clean up its profits, but was not part of its inner circle.

He will be sentenced on July 22.

Bowler, of Kingston-upon-Thames, Kinnimont, of Surbiton, Surrey, Moran, of Fulham, west London, admitted conspiracy to import drugs and money laundering.

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drugs baron who created the 'Tesco' of cannabis smuggling is facing up to 20 years behind bars.